Telephone switch-board



(No Model.) 2 Sheets-Sheet 1f.

P. J. ROUSSEAU.

TELEPHONE SWITCH BOARD.

No. 304,135. Patented Aug. 26, 1884.

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2 Sheets-Sheet?. B J. ROUSSEAU.

TELEPHONE SWITCH BOARD.

' (No Model.)

Pamted Aug. 26, 1884.

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UNITED STATES Parenti* Ormea PAUL J. ROUSSEAU, OF DETROIT, MICHIGAN.

SPECIFICATION forming part of Letters Patent No. 304,135, dated August 26, 1884.

Application filed FebruaryY l1, 1882.

To all w/wmf t may concern.:

Be it known that I, PAUL J. ROUSSEAU, of Detroit, in the county of Wayne and State or Michigan, have invented new and useful Improvements in Telephone Switch-Boards; and I do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawings, which form a part of this specification.

This invention relates to certain neuT and useful improvements in the construction and operation of switch-boards for telephonie purposes.

The invention consists in the peculiar construction, combinations, and operation ofthe parts which form my improved switchboard, as more fully hereinafter described. 'With the sivtclrboards which are now in common use, vrhen any subscriber on one board desires to talk. with a subscriber on any ofthe other boards, the operator whose subscriber Wants the connection Writes upon a check his number and the number thesubscriber Wishes to talk with, and sends the same by messenger to the operator who has the second subscriber on his board.

The object of my invention is to dispense with the service of a messenger, the necessity of Writing such checks, and all the delay and confusion caused thereby, and enable each operator on each board to himself make any connection desired with any other subscriber on another board.` For this purpose I have constructed an attachment to each boa-rd, which I call a duplicating attachment;77 and it contains the number of each subscribed on the other boards, aud is connected and operated as hereinafter described. By the use of my attachment an operator who has the usual switch-board, with iftysubscribers, is enabled to make the necessary connections readily, easily, and quickly with fifty times that number. For the purpose of illustration, I have represented a switch-board with ten subscribers and a duplicating attachment for thirty more subscribers, which, together, represent forty, subscribers equally divided on four boards.

In the accompanying drawings, Figure l is a representation of portions of a switch-board with my duplicating attachment applied thereto. 2 is a perspective View of a portion (No model.)

of the key-board. Fig. 3 is a perspective View of one of the duplicating-strips. Fig. 4 is a diagrammatic view showing the manner of making and the system of connections in a local circuit.

A represents the switch-board, and B my duplicating attachment, the Whole consisting of the strips C D E F and crossbars H I K C T G. The strips C'l D E F are of like construction; but While each strip C represents only one line entering the oihce each of the strips D E F represents ten subscribers or ten lines. In Fig. 3 one of these strips is shown in projection. It consists, like all the others, of the insulating-plate c, metal plate b, secured thereto, spacing-pins c, and holes d, for the passage of the crossbars, all of known construction and operation. For the duplicating attachment these strips are subdivided into sections by the saw-kerfs c, which separate the metal plate Z into ten sections. Each section has a Wire, f, secured thereto, Which con nects each section with all the corresponding numbers on the other boards. The cross-bars II are made long enough to pass through the duplicating strips in the same manner as through the strips C. Around and on top the duplicating attachment indexing-plates are secured.

On switch-board No. l in the drawings thc duplicating attachment has as many sections as there are subscribers on the other boa-rds, and they are numbered correspondingly, and the same conditions pertain to the other boards. The strips G' have, in addition to the regular cross-bars H, the bars I K O T G, of which I and K are for the use of the subscribers on the board, so as to put them into connection, and four subscribers can be put into connection in these two bars, although any of the ten bars H `might be used for the purpose. Still I provide the two bars I and K, so as to prevent any possible interference with the operation oi" the duplicating attachment.

C is the call or generator' strip. T is the telephonebar; G, thc ground-bar, all connect ed and operating as usual.

L is a key-board of the construction shown in Fig. 2 in perspective. It is placed under the ground-bar Gr in such position that when a line is grounded by the plug .r (see Fig. Li, section y y) the key is depressed, thereby elec- IOO ACO

trically connecting the short circuit i with the wire K, and to prevent an y current passing through the plug the forward end ofk the spring vm has a rubber tip, g.

i is a short eircuit,which connects each subscribers line, before it passes to the annunciator, with the contact K of the hey g, which is under ,the ground strap or bar G.

K lli is a local battery to which the wire 7L'. is permanently connected.

N are so-called soundersj one for each board. One ol' the poles ot' the battery M connects with all the sounders, while the other connects by the line K with the key-boards L. Each sounder has attached to that pole which is not connected to the battery a testplug, o, and in addition thereto each subscribers line is provided with some well-known form of annunciater or visual signal., as indidicated at 13, Fig. Li.

rlhe arrangement and operation ofthe testcircuit is as follows. Suppose the operator on board No. 1 is called up by subscriber 9 to make connection with subscriber 13, which is not on his board but on No. 2, first No. 1 throws olf the ground ot" No. 9 by taking out the ground-plug fr. At the end of each subscribers strap, and below the ground bar, is placed a cireuit-ln'eaker, which consists ofthe metal. spring on', contact-strip K, rubber tip y, and insulating-base L. rlhe metal spring m is connected to one end ol" a wire, L', the other end of which is connected to the local battery M, and said spring, when depressed, connects with a short-circuit line, v which is connected to the subscriber-s line before the latter enters its aununeiator.

The function of the ground-plug :r is twofoldf-iirst, by being inserted at the groundbar, as shown in, the drawings, it grounds the subscribers line by making electrical contact between the contact-pin c and the groundbar. As all the lines have to be normally grounded, there is therefor a ground-plug inserted at the end of each strap when the line is in its normal condition. The second function ofthe ground-plug is a mere mechanical one, and is a co-function of the iirst one, obtained yby placing the circuit-breaker in proper position in relation to the ground-plug, so that thelatter, at the same time that it grounds the line, also brings the spring ym in Contact with the contact-piece K, and thereby establishes electrical connection between the battery-wire It' and the short-circuit wire '11.

rEhe operation ofthe test-circuit is as follows: Suppose the operator on. board No. 1 is called up by subscriber 9 to make connection with subscriber 13, which is not on his board, but on No. First, No. 1 throws oft' the ground ot' No. 9 by taking out the ground-plug 1r; then he inserts the test-plug o at the proper place on his supplementary switch-board, so as to malte electrical connection between the testplug and the terminal at the trunk-line of subscriber 13. New, if the line of subscriber 13 is not in use, the ground-plug .c on this line will be in place and a closed battery-circuit be found to exist, which is indicated on the drawing by arrow-heads marked along the line of said circuit. The fact ofthe existence of this closed battery-circuit is made evident to the operator of No. 1 board by the operation of the sounder N. Then operator No. 1 removes the test-plu g o and puts the generatorplug T3 in its place. As this circuit is completed through the ground, it will pass through subscriber 13s trunk-line, enter through theY annunciator, and pass through the strap and ground-plug of subscriberlsground. No. 2 operator, upon seeing the shutter of subscriber 13's annunciator drop, removes the groundplug as, an d therebygivcs the operator on No. 1 board possession oi" subscriber 13s line. The operator on No. 1 table proceeds then as usual-that is, he connects subscribers 9 and 13 on a corresponding talking-bar by plugging in. The operator on No. 2 table cannot be mistaken about the nature of the call which has operated the annuneiator of No. 13, as the continued action ofthe armature, which is under the intluence of a generator-current, tells him plainly that the call is for a local connection, which requires no further attention from him than the removal of the groundplug and its ultimatereplacing when the subscribers are through talking. The operator at board No. 1, after having kept his generator-plug in place the usual ten or fifteen seconds, takes it out and puts an ordinary plug in its place, leaving the two subscribers7 lines connected through the o'tiice by one plug from the entering or calling subscriber s strip to the transverse talking-bar H, and by another plug from said transverse bar to the proper section. of the duplicating-strip, which is permanently connected to the second or called subscribers strip, and so completes the connecting of the two lines when the ground-connections are removed.

Although I'have shown in the drawings my duplicating attachment so combined with the switch-board as to make anl integral part thereof, this need not necessarily be the case,

.as my attachment may form a'separate board,

being only connected with the switch-board by wires representing the cross strips or bars. I also do not desire to confine myself to the construction of the duplicating-strips shown in Fig. 3, as a number ot equivalent construetions maybe employed; but for the sake of simplicity and uniformity prefer to form my duplicating-strips inV imitation of switchboard strips, so as to allow the whole to be readily combined in one board by simply extending the transverse bars therethrough.

Wvhat I claim as new is 1. A telephone switch-board and circuitconnecting apparatus divided into separate sections, each section composed partly of par allel strips, each representing one entering or subscriber s line, and partly of similar parallel and auxiliary strips divided into sections, each of said sections representing a line en- IOO IIC)

tering a different division of the apparatus, and a series of conducting,` or talking` bars extending transversely throilgh the entire parallel series, and adapted to connect any tWo of the parallel strips or sections by the insertion of suitable plugs between said strips and bars, and au additional transverse bar, to which all of the enteringdines are normally connected and grounded, substantially as set` forth.

2. A telephone switch-board and circuitconnecting apparatus divided into separate sections, each section composed partly of parallel strips normally grounded, and each representing an entering or subscribers line, and partly of similar and auxiliary strips divided into sections, cach sect-ion forming part of a circuit common to all the divisions of the apparatus and including a subseribers line entering a different division of the apparatus, and a series ot' conducting,` or talking loarsextending transversely through the entire series oi' parallel strips or sections, and an inde pendent testing-circuit including a sounder and battery, and adapted to be connected from one division of the apparatus to the subscribers line-wire of another division through the corresponding auxiliary section, and a local short circuitcontrolled by the grounding device of the entering-strip, substantially as described.

3. A connecting-strip for telephone switchboards, consisting` of the insulating foundation-strip a and the metal strip b, divided into two or more sections, and provided with pins c, secured thereto, and the transverse apertures d, substantially as shown and described.

4. The combination of the apertured strips C and transverse talking-bars H with the key-board L, local short-circuit wire t', the grounding-bar G, and suitable contact-plug, and the local battery-sounder and independent testingdine, substantially as shown and described. v

5. In a telephone system, a series of incchanical circuit-breakers arranged below each line of straps of the switch-board, and adapted to be operated in combination with the gronndplugs, all so arranged that the insertion of the latter to ground or ungronnd the lines also operates the circuitbreaker, substantially as and for the purposes described.

6. The local sliort-eircuiting device consisting of the key-board L, having keys or springs m, provided with insulated tips located below' the groundingbar G and permanently connected to the wire l; of the local battery, in combination with the contact K, wire t, and suitable trunk-line, whereby the insertion of the groundingplug will depress said key until it rests upon the contact K, and thereby close the local short circuit, as set forth.

7. The normally-grounded entering` or subscrbersstrips G, in combination with the transverse connecting-bars I K, groundingbar G and suitable plug, and the bar T and suitable annuneiator, substantially as shown and described. l

PAUL J. ROUSSEAU.

Ni tn ess es H. S. SPRAGUF., E. ScULLY. 

